Refrigerating apparatus



Nov. 13, 1928. 1,691,286

N. H. HILLER REFRIGERATING APPARATUS Filed ov. 25, 1927IIIIIIIIIII'IIIIIIIIII- INV ENTOR ATTORN EYS Patented Nov. 13, 19 28.

' UNITED STATES NICOLAI H. Human, orcAnnoNnALE, rENNsYLvANIA. I

BEFRIGERATING ArrAnA'rUs.

This invention is an improvement in refrigerating apparatus of thecompression type, in which so-called multiple efiectHs employed asdisclosed in the Voorhees Patent No. 7 93,864. By permitting theevaporation of a portionof the liquefied refrigerant in a mutiple effectreceiver or precooler, the remainder ofthe liquid is cooled to a temperature much lower than that of the condenser 10 before going to theevaporator. The same compressor takes, at one end of the cylinder, thegas from the evaporator, while at a oint intermediate of the ends of thecylin er it takes the gas at a higher pressure from the receiver.

The invention relates more particularly to the construction of theprecooler or multiple eflect receiver, and to the control of thepressures in this part of the system.

In orderto get the maximum capacity and -efiiciency, two conditions arenecessary. First, nothing but'li'quid should be fed from the condenserto the receiver, and second, nothing but liquid should be fed from thereceiver to the evaporator. The first condition is readily obtained bythe use of an ordinary automatic pressure regulator, because if therefrigerant be pure, and suflicient pressure be maintained in respect tothe condenser so temperature, all of the refrigerant gas will beliquefied in the condenser and may flow by gravity to the receiver. Thesecond condition ma e obtained by the use of a float t pe of regu atorwhich-will maintain liqul in.

the receiver and at the same time permit any SUIEUS liquid to passtrgzhe evaporator. the condenser pressure when carbon dioxid (C0,) isused as the refrigerant may be 1,000pounds, and the evaporator pressure0 my be 300 pounds, it will be noted that there w' be a ver considerabledifference between the interme iate ressure in the receiver, and theopposite ext me pressures of the condenser and the evaporator. If thevalve controlling the outlet from the receiver to the evaporator be ofsuch size that it will permit the desired rate of flow for a larcapacity apparatus, a large float is require to operate the valveagainst the pressure difference, and

as this requires a correspondingly large precooler or iuteririediatereceiver.

' The main object of my invention is to permit the use of smaller,cheaper and simpler parts, and I accomplish this object by a novelcondenser temperature is maintained.

Application filed November as, 1927. Serial No. 235,208.

one, and arrange the float operated valve so that it works against onlythe pressure diflerence between the two intermediate pressure stages. Iplace the float operated valve and a separate spring pressed valve inseries in the 1 outlet passage from the precooler to the evaporator.Thus, between the two valves there will be a pressure higher than thatof the l I evaporator and lower than that of the re celver, and the workdone by the float is only that required to overcome the pressuredifierence' between this intermediate pressure and that ofthe receiver.Therefore, a smaller, cheaper and simpler float and a smaller'pre- 'llcooler may be employed.

the accompanying drawin I have shown somewhat diagrammatical y anapparatus embodying myinvention. In this apparatus there isemployed theordina' type of multiple eflect compressor 10 whic is preferably doubleacting, and receives the low pressure gas through a conduit 11 from theevaporator 12. he compressed gas 4 passes through a conduit 13 to acondenser 14 a5 where it is liquefied, and flows to a precooler ormultiple efl'ect receiver 15 The li uid passes b a conduit 16 to theevaporator w i e gas pro need by the precooler or the receiver 15 goesby a conduit 17 to the compressor cylno inder at a point intermediate ofthe ends of the latter. All of these parts to the extent so fardescribed may be of any ordinary type A well' known-in the art.

In carrying out my invention'there is pro- '95 vided an automaticpressure regulating valve 18 between the condenser 14 and the receiver15 which may be set so as to maintain the desired pressure required inthe condenser for liquefaction of the refrigerant under the con- 10odenser temperatureused. This prevents the I delivery of any .unliquefiedgas from the condenser to the receiver, so long as the refri'gerant'remain comparatively pure and the I ,In the outlet-passage from thereceiver to the evaporator there are provided two separate valves;arranged in series. The first valve 19 is float-operated, while theother valve 20 may be of the ordinary automatic pressure regulatingtype.

The receiver illustrated is provided with a transverse partition 21 fromwhich depends a conduit 22, the lower end of which is in a float 23 ofthe bucket type. The gas outlet conduit 17 leads from a point directlybelow the partition 21, while the conduit 24 in which the valves 19 and20 are located, leads from abovecthe partition. The float 23 isconnected to thevalve 19 in any suitable manner, as for instance by abell crank lever 25 and a pair of links 26 and 27.

Assuming that carbon dioxid be the refrigerant employed, the pressure inthe condenser and up to the valve 18 may be approximately 1,000 pounds.The pressure in the evaporator beyond the valve 20 may be approximately300 pounds. By means of the valve 19 which is between the valves 18 and20, the pressure in the receiver may be approximately 600 pounds and thepressure in the conduit 24 between the valves 19 and 20 may beapproximately 500 pounds. When the pressure in the condenser: exceedsthe limit of the valve 18, the liquefied refrigerant will flow into thereceiver until a sufficient amount is accumulated to cause the valve 19to open. Liquid will then flow up the conduit 22 and through the conduit24 to the valve 20 which will open if the pressure is above 500 pounds,and the liquid will flow on to the evaporator. When the liquid level inthe receiver drops to such a point that the valve 19 closes, gas under apressure of approximately 500 pounds will be held in the conduit 24because it cannot escape at that pressure past the valve 20. Thus, whenliquid has accumulated to a point when the float again opens the valve19, it will open it against a pressure difference of only approximately100 pounds, namely the difference between the 600 pounds pressure of thereceiver, and the 500 pounds pressure of the conduit 24. A

comparatively small float isample to operate the valve a ainst pressuredifference.

- Although from the above description of the operation it might appearthat the opening and closing of the several valves is effectedintermittently, it will be understood that in practice under normaluniform conditions all of these valves will remain substantially at restin a partly open position to maintain substantially constant and uniformflow and the desired pressure differences. If desired,

this comparatively small the main flow from the receiver to theevaporator may be through a conduit 28 controlled by a manual orautomatic valve 29, and the float actuated to open the valve 19 andpermit an extra flow only in case liquid accumulates in'the receiverabove a normal operating level.

I do not wish to be restricted to any parsaid third mentioned ticulartype of float, and have used the term float in a broad sense. Theparticular float shown is of the bucket type which rises when the liquidlevel outside of the bucket is high and the level in the bucket is low,due to withdrawal therefrom through the conduit 22. In normal operationthe level outside of the bucket will be such that the liquid willoverflow into the bucket at substantially the same rate that it flowsout of the bucket through the conduit 22. Any type of float which willopen the valve 19 on high liquid level in the receiver might beemployed.

Although in practice only a single valve 20 is used, it will be apparentthat two or more such automatic pressure reducing valves might beemployed in series, so that the pressure difference against which thevalve 19 operates might be still further reduced.

To facilitate illustration, the valves 18 and 20 have been shown spacedfrom the receiver, although in practice it will be obvious that thevalve 18 might be directly at the inlet of the receiver, and the valve20 might be in the same valve casing with the valve 19, or might be atthe inlet of the evaporator proper.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A refrigerating apparatus of the multiple effect type, including areceiver having a liquid inlet from the condenser, a liquid outlet tothe evaporator, and a gas outlet to the compressor, a float operatedvalve for controlling said liquid outlet, and an automatic regulatingvalve intermediate of said first ,cally maintained between said floatvalve and valve, higher than that of the. evaporator and lower than thatof the receiver.

3. A liquid receiver for use in refrigerating apparatus, said receiverhaving a liquid inlet, a spring pressed valve for controlling the same,valve for controlling said outlet, and a spring pressed valve beyondsaid float operated valve whereby a comparatively small difference inpressure may be maintained upon opposite sides of said float operatedvalve.

4. A liquid receiver for use in refrigeratin apparatus of the multipleeffect type, inclu ing a receiver, a conduit for delivering liquid thereceiver, and an a liquid outlet, a float operated therefrom to anevaporator, and a float operated valve and a separate sprin pressedconduit having a float operated valve and a valve arranged in serles forcontrodling said spring pressed valve in series for controllingdelivery. the same.

5. A refrigerating apparatus of the multi- Signed at Carbondale, in thecounty of 5 ple eifect type, including a receiver having a Lackawannaand State of Pennsylvania this main liquid outlet conduit, means forcon- 21st day of November, A. D. 1927. trolling the same, and a secondliquid outlet NICOLAI H. HILLEB.

